Soldering apparatus



April 25, 1944- P. w. cRls'r ETAL 2,347,397

SOLDERING APPARATUS Filedy Dec. 3l, 1942 2 Sheets-Sheet April 25, 1944.v P. w. c'RlsT l-:rAL

SOLDERING APPARATUS Filed Dec. 31, 1942 2 Sheets-Sheet 2 FIG. 6

INVENTORS RW C19/$7' 6. JOHA NSSON A T TOR/VFY Patented Apr. 25, 1944 SOLDERING APPARATUS Philip W. Crist, Roselle Park, and Sven G. Jo-

hansson, Cranford, N. J., assgnors to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application December 31, 1942, Serial No. 470,890

2 Claims.

This invention relates to soldering apparatus, and more particularly to apparatus for soldering to an elongated member another member in such fashion that the mass of solder used will be accurately located in a predetermined position on the elongated member.

In the electrical arts and particularly in the communications arts, use is made in a variety of apparatus of small slabs, slices or plates of crystalline substance, especially crystalline quartz, having a metallic film on each of the broadest flat sides of the plates. Such a slab or plate is known, for short, in the art as a crystal; and the word crystal will be used hereinafter and in the appended claims to mean such a slab, slice or plate of crystalline dielectric substance having a closely adherent meta1 lm on each of its two broadest opposed faces. To support mechanically such a crystal and to afford electrical connection to its metal films, metal wires, perpendicular to the iilm faces, may be butt-welded to the films as primary connector supports. To locate and support such a unit in an apparatus, in some instances, and to provide electrical connections thereto, the primary connector supports may be conveniently soldered to other mechanically supporting and electrically connecting Wires, as secondary connector supports. Such a secondary support may be a Wire having one end thereof abutted endwise against or laid laterally against a primary connector support of the crystal and soldered thereto. Such crystals when in use are frequently subjected to alternating potentials applied across their films. One effect of this is that the crystal is given a mechanical vibration which may be transmitted out through both primary and secondary outputs and affect the apparatus undesirably. To obviate such effects, the soldered connection of the secondary support to the primary support may be made with a bulk of solder of such predetermined mass and located at such predetermined distance from the adjacent crystal face that mechanical vibrations traveling out the primary support from the -crystal will be absorbed in, i. e., damped out by, or will be totally reflected by the solder mass and thus not transmitted to the secondary support. The predetermined mass and distance involved will, in each case, depend upon the frequency of the mechanical vibration in question, which in turn will depend upon the frequency of the potential applied across the crystal.

An object of the present invention is to provide an apparatus or device whereby a member may be quickly, eiiiciently and accurately soldered to an elongated member with an accurately predetermined mass of solder located at a precisely predetermined site on the elongated member.

-With the above and other objects in View, the

invention may :be embodied in an apparatus comprising a horizontally disposed soldering iron tip, made of metal, such as aluminum, unwettable by molten solder, and formed in its upper surface with a cup-like recess or hollow opening from one side face of the tip, in combination with a removable :fixture member also of material unwettable by molten solder dimensioned to be applied against the said side face of the tip and formed to receive and hold transversely thereto an elongated member to extend into the cuplike hollow and to hold another member in contact with the elongated member at the side opening of the hollow.

Other objects and features of the invention will appear from the following detailed description oi' one embodiment thereof taken in connection with the accompanying drawings, in which the same reference numerals are applied to identical parts in the several iigures and in which Fig. 1 is a view in side elevation of an apparatus constructed in accordance with the invention;

Fig. 2 is a plan view thereof;

Fig. 3 is a view in side elevation of an article to be soldered in the apparatus of Fig. l on an enlarged scale;

Fig. 4 is an end view thereof;

Fig. 5 is an enlarged view in side elevation of the article holding means of Fig. l;

Fig. 6 is an end view of the parts shown in Fig. 5 with the secondary supports omitted;

Fig. '7 is a plan View thereof with the tip of the soldering iron added;

Fig. 8 is a side elevation to show the relation of the article to the soldering iron tip in operative position;

Fig. 9 is a much enlarged plan view of the article holding member;

Fig. 10 is an end view of the showing of Fig. 9;

Fig. 11 is a front elevation thereof; and

Fig. 12 is a View similar to Fig. 7 of a modified form.

The apparatus herein disclosed and described as an embodiment of the invention and generally illustrated in Figs. 1 and 2, is particularly constructed and adapted to deal with the article illustrated in Figs. 3 and 4. AAdescription and discussion of this latter, as a preliminary, will simplify the description of the apparatus and render clearer the problems, purposes and operationsginvolved, although the article is not in itself a part of the present invention, being disclosed and claimed in copending application Serial No. 470,759, filed by Irvin E. Fair on December 31, 1942.

, The article illustrated in Figs. 3l and 4 is a crystal mounted to be assembled as part of an electrical apparatus. It comprises a thin, square, slice, slab or plate 20 sawn from crystalline quartz and ground to predetermined dimensions, each of the two large faces 2| and 22 of the plate being Aprovided with a tightly adherent film of metallic silver, too thin to' be represented in the drawings but covering the whole face on which it is applied. To the center of each of these lm covered faces 2| and 22, is soldered or welded one end of a straight bit of wire 213 and 24, preferably bronze, which extends out perpendicularly to the plane Yof the face on which it is secured. These are secured to their respective metal lms by small convex beads and 26 of solder or of added Welding metal. The structure thus far described is called a crystal for the purposes of this application. The wires 23 and 24 are lthe `primary connector supports. The article now under consideration also comprises a base member 21 of suitable'insulating material in whichare rigidly mounted two metal connector pins 23 and 29 extending through the base 21 to form plug terminals onthe left side (Fig. 3) and mounting heads on the right side. To the mounting lheads are soldered respectively two spring wire members 3i) and 3|. The member 36 is C-shaped and the member`3| is shaped like a gure 2; and these are so disposed that both arch inthe same sense of curvature toward their outer endsfwhich abut sidewise respectively against the primary support wiresV 24 `and 23 near the outer ends of these and are secured there respectively by beads 32 and 33 lof solder. The wires 36 and 3| are the secondaryconnector supports of the crystal.

In assembling the article shown in Figs. v3 and fl, the crystal, generally indicated at 34, and the mount, generally indicated at 35 in Fig. 3, are each assembled separately, the crystal 34 including the quartz'l plate 26 with its metal lms on the faces 2| and 22. and the primary connector supports 23 and 24; secured to the films at 25 and 23, while the mount includes the base 21, pins 26 and 2S, and the secondary connector support wires 33 and 3| soldered on the pins.v The nal step of the assembly is to solder the supports 23 and 3| together at 33 and the supports Zl and 33 together at 32. n

In performing this last step of assembly it is importantly necessary to locate the solder beads 32 and 33 respectively on the vprimary supports 2t and 23 so that the'inner sides of the beads and their centers of mass will lbe spaced from the respectively adjacent, film coveredfaces of the crystal plate at accurately predetermined distances. It is to the meeting-of this particular requirement that Ythe apparatus herein disclosed in detail is directed. y

The apparatus 4comprises two principal ycooperating units, a soldering means proper, shown at the right in Figs. 1 and 2, and a xture to hold the units `35| and 35 in proper relation to each other and bring them so held into correct `operative relation with the soldering means. The xture unit is shown at the left in Figs. 1 and 2.

The soldering unit comprises an electrically heated soldering iron of which only the shank 35 and the tip 31 are shown. The heating means, handle, if any, power cable, etc. are not shown, being of ordinary and familiar construction. The shank 36 is rigidly and horizontally mounted in a suitable perpendicular pedestal 38 on a base 39. The tip 31 is specically adapted and formed to the 'special purpose in hand. There is in theleft end of it a vertical, central, parallel walled slot 4|, so that the bifurcated tip Ahas -twin noses 42 and 43. Each Anose is formed on its upper surface with a hollow or recess 44 and 45 enclosed by upwardly slanting walls on all sides except toward the slot 4|, where each of the two recesses is open to its bottom. In the particular device illustrated the recess 44 (45) is formed by two sloping planes 46 and 48 (41 and 49) meeting along a line 5|! (5|).

For convenience a shallow metal tray 52 is mounted on the shank 36 by a metal sleeve 53 to be kept hot by heat from the shank. Pellets of solder of predetermined mass are kept in this tray in a bath of stearic acid kept liquid by relatively gentle heat maintained from the shank 36, which bath serves to protect the solder pellets against atmospheric oxidation and also xto Aact as a flux during the soldering operation.

The fixture unit comprises a pedestal 154 xon the base `35| in which is mounted asupport55 pivotable about a horizontal-axis in thepe'des'tal and having means as shown to hold the support yieldingly in either ofthe two extreme positions shown in Fig. l, andmovable from theone-position to the other by means of a handle 5&5. lln the right side of the support 55 is'an L-shape'd member 51 adjustably slidable in a'corresp'on'ding slot in the-support '55 andheld therein vin adjusted position by means of .a clamp 58 and screw 56. rlhe outer limb 63 of the member 751 stands across and adjustably spaced from the upper end oi the support 55. The vupper Vend of the support 55 is provided with Ya vertical central slot 56 dimensioned to receive the pins 28 and 2t respectively of the unit 35 vor' -the article snugly but easily. Contacter theunit base 21 with the member 51 and against 552as indicated at 6i positions the unit 35. A spring clamp 62 secured on the front of the support 55, enters through a slot in the support as shown to clamp the pins 28 and 29 yieldingly iny place when inserted into the bores 6| vandll.

The tip end of the transverse limb V63 of the member 51 is shown vin much enlarged detailin Figs. 9, 10 and l1, as well as on a smaller Ascale in Figs. 5, 6 and 7. This upstanding limb 6311s rectangular in cross-section and tapered slightly upwardly from front to back so that its 'width from front to back increases slightly from the top edges 64 and65 to lines E6 and 61from where on down this widthis constant. The'width o'f the slot 4| between the noses 42 and 43 of l'the soldering iron tip 31'is such as to-receivefthe llimb 63 easily at this constant widthbelow the lines 66 and 61 and leave easy space between but Ano more for the ends-of the wires 3i) and 3|. 'Af-V- shaped groove is cut longitudinally andrcentrally across the top end of 51and-a second'V-shaped groove is cut centrally and transversely thereto, so that the four corners of-.the top present downwardly centrallyslanting faces .68, 69, 10 and .1| formed by the first named-'groove andsimilar faces 12, 13, 14 and 15 formed bythe secondgroove. From the bottom of the iirstgroove a longitudinal central slot 16 extends downl andterminat'es .in a cylindrical bore 11. A similarv slot -18 trans-verse thereto leads down from the bottom of the transverse groove. A vertical central bore 19 Af-rom'the top down also terminates in thebore'11.

These various elements of the tip ofth limb 63 are so formed, proportioned and related that a crystal 34 may be inserted, as shown in`Figs.l-5, 6 and', easily and removed easily and yet'fbeheld substantially immovably while the soldering-'operationlis done. The slot 16 is wide enough'to just receive the 'plate `'Mlleasilm :and the bottom of the bore 11 is so located as to support the plate in the slot in the position shown in Figs. 5, 6 and 7. The slot 18 is wide enough to just receive the primary connector supports 23 and 24 easily. The bore 19 provides clearance for the weld blobs 25 and 26. The slot 18 is merely clearance for the wires 23 and 24 and extends down below these, the crystal unit including these wires being sup ported by the bottom edge of the plate 20 resting on the bottom of the bore 11. The wires or primary connector supports 23 and 24 then extend out through the front and rear faces of the member 53 at or just above the lines 86 and 61 where the member begins to taper. Hence after the soldering has been done and the solder blobs 32 and 33 formed, as hereinafter described, against the very slightly tapered faces of the fixture member 63, the soldered structure may be more easily lifted up out of the xture because of the taper. In practise this taper is very slight, e. g., 0.003 inch taper per inch of length.

In operation, a crystal unit 34 is seated in the xture member 63 in the position shown in Figs. 5, 6 and '7, the inclined plane surfaces 68-69 and 1li-1| acting as guides to lead the edge of the plate 2U into the slot 16, and the surfaces 12-15 and 13-14 in like manner acting to guide the wires 23 and 24 into the slot 18, while the weld blobs 25 and 26 pass down the bore 19. A companion unit 35 is placed in the end of the meinber 55, as shown in the same ngures, with the outer ends of the secondary connector supports 3| and 3!) pressing gently to the right (Fig, 5) against the outer end of the primary connector supports 23 and 24 respectively just outside of the member 63. The wires 3| and 30 are formed to press themselves resiliently and lightly but rmly against the member 63 as well as against the wires z3 and 24.

The member 55 is then swung down from the loading position shown in full lines in Fig. l to the soldering position shown in dotted lines. A pellet of solder of predetermined mass is picked from the tray 52 and laid in each of the cups or recesses 44 and 45. The soldering iron tip 31 and particularly its twin noses 42 and 43 in which the cups 44 and 45 are, is kept at soldering temperature; and thus the solder pellets, covered with stearic acid ux from the bath in the tray 52, are melted in the bottom of each cup and around the cross contact of the Wires 23 and 3| and of 24 and 30 respectively. The special relation of these contacts to the cups is shown in Fig. 8, from which it will be noted that the various parts are so adjusted that in the soldering position shown, the ends of the wires 23 and 24 project horizontally into the cups 45 and 44 respectively suiiiciently above the lowest points of the concave cup bottoms to allow the molten solder to iiow under the wires 23 and 24 and thus form a solid union of the crossed soldered elements. As soon as the solder is fairly melted and has thus run wholly around the horizontal wires, the member 63 is again lifted out of the slot 4|. The molten solder by then is held in place, where put, by adhesion to the crossed wires and by its own surface tension, and sets in this position to form the accurately positioned blobs 32 and 33.

The fixture unit of the apparatus holds the contact points of the wires to be soldered in a predetermined position relatively to the plate 20 and, by forming a removable temporary wall for each of the cups in which the solder is melted,

also determines the distance between each face of the plate and the nearest surface of the solder blob adjacent thereto.

If the solder masses in question are too large to permit of depending upon internal forces of adhesion, cohesion and surface tension to hold the molten solder accurately enough in situ when the fixture is raised out of the soldering unit to cool the solder, the parts may be left in the soldering position, the power supply to the soldering iron out 01T, and the combined members 63 and 31 chilled by a blast of cold air or other suitable means, to cause the solder to set, and the members '53 and 31 be then separated to unload the one and reheat the other.

It is to be noted that the members 63 and 31 must each be of some material not wetted by molten solder, e. g., aluminum, iron or steel with its surface phosphatized, stainless steel, aluminum bronze, chromium plated other metal or the like.

Fig. 12 is presented to illustrate the fact that it is not necessary to have the soldering iron bifurcated or to perform two solderings at one operation in order to embody the invention. In this arrangement some generally T-shaped unit |34 is to be soldered at |32 to a wire |3I. The soldering iron tip |31 has only one nose |42.

If, in Fig. l2, the wire |3| and its support be omitted, the device serves to place a predetermined mass on the wire |24 at a predetermined distance from the adjacent face of the plate I 34.

Other modifications and variations of embodiment may be made without departing from the spirit and scope of the invention as particularlyr pointed out and described in the appended claims.

What is claimed is:

1. In a soldering apparatus, a vertically slotted heatable member of material unwettable by molten solder and having two recesses in the top surface thereof opening respectively also from the two side surfaces of the slot, in combination with a fixture unit comprising a support movable into and out of the slot and proportioned to substantially close laterally the two recesses, means on the support to hold an element to be soldered with a part projecting horizontally into each of the two recesses when the support is in its recess closing position, and means on the support to hold another element to project vertically into each recess adjacent to the part of the first named element therein when the support is in recess closing position.

2. In a soldering apparatus, a vertically slotted heatable member of material unwettable by molten solder and having two recesses in the top surface thereof opening respectively also from the two side surfaces of the slot, in combination with a fixture unit comprising a support; movable into and out of the slot and proportioned to substantially close laterally the two recesses, the support having a slot therein to reach from recess and recess and dimensioned to receive the primary support wires of a crystal unit and having a second slot at right angles thereto and dimensioned to receive and support the plate of the crystal unit, and means on the support to hold a crystal mount unit having secondary support wires thereon with the ends of the said wires adjacent to the primary support wires of a crystal unit in the said slots.

PHILIP W. CRIST. SVEN G. JOHANSSON. 

